Global Climate Model Validation, Forecasting and Uncertainty

This is the first of a series of talks concerned with climate models, the forecasts and scenarios they are used to produce and the validity of such models.

Introduction

Validation and Forecasting in Climate Models

Robert Fildes

Director, Lancaster Centre for Forecasting

Atmospheric-Ocean General Circulation Models (AOGCMs) are increasingly used to produce forecasts over the medium-long term (10-100 hundred years ahead). The resultant conditional forecasts are then used as the basis for policy discussions. This brief introduction will discuss the issue of the validation of such models and the role of forecasting research in validation.

Predicting the Climate of the Coming Decade

Doug Smith

Met Office, Hadley Centre

The next IPCC assessment report (AR5) will include, for the first time, a focus on decadal-scale climate predictions. A major advancement in the IPCC-AR5 simulations relative to previous efforts will be an attempt to predict natural internal climate variations in addition to changes forced by anthropogenic greenhouse gases. In order to assess the likely skill of forecasts of the coming decade a comprehensive set of retrospective forecasts (hindcasts) with start dates covering the period 1960 to 2005 has been performed using the UK Met Office global coupled climate model. Results of these hindcasts will be summarised in this talk, focusing particularly on additional skill arising from predictions of natural internal variability.